1. Field of the Invention
The present invention relates to an additive service of a public phone communication system and, more particularly, to an apparatus and method for providing a bi-directional Calling Identity Delivery (CID) service.
2. Background of the Related Art
A CID service is intended to display a phone number and a name of a caller, before initiating a call communication or during a call communication, on a display terminal unit of a destination service subscriber. The CID service does this by utilizing an automatic number identification function of a phone network, which function is used for a special purpose such as billing for another provider""s relay call.
In addition to providing a data service to an analog subscriber, the CID service field anticipates a considerable technological and industrial effect for a terminal related to computer telephony integration (CTI), which has been recently activated.
FIG. 1 is a schematic block diagram of a CID service unit in accordance with a background art. The background CID service system includes a CID unit 100 of a destination phone set that displays caller information of a destination call. A CID data processing unit 210 generates caller information (termed xe2x80x98CID data,xe2x80x99 hereinafter), such as a caller phone number, a caller name, and a call date/time, and transmits the CID data to the destination telephone set.
The CID unit 100 of the destination phone set includes a CID modem 130 that receives CID data from the CID data processing unit 210; an LCD panel 110 that displays the CID data received through the CID modem 130; a controller 140 that controls various signals, data transmission, and a display operation of the CID data; and a call circuit unit 120 that controls a call set-up related to the caller, according to a call control signal of the controller 140. The CID unit 100 may be inserted in the destination phone set or may be installed separately from the destination phone set. The service operation of the CID system of the background art will now be described in detail.
When the caller dials a subscriber number to be called, a pertinent intra-office exchange 300 generates a xe2x80x98call connection request signalxe2x80x99 and transmits it through a transmission line to the CID data processing unit 210 of a pertinent called party exchange. While receiving the xe2x80x98call connection request signal,xe2x80x99 the CID data processing unit 210 searches a CID service data base DB) (not shown) to check whether the corresponding caller has been registered in the CID service DB. If the caller has been registered in the CID service DB, the CID data processing unit 210 generates CID data, such as a caller number, a name, or a calling date/time, and transmits the CID data when a ring signal is transmitted to the call circuit unit 120 of the destination phone set (between a first ring signal and a second ring signal). The transmitted CID data is transmitted to the CID modem 130.
The CID modem 130 performs a frequency-shift keying (FSK) demodulation and a predetermined signal-conversion for the received CID data and displays the CID data on the LCD panel 110. Then, the subscriber can be aware of the caller, by checking the content displayed on the LCD panel 110.
Data transmission between the CID unit 100 of the destination phone set and the destination exchange 200 is made using the FSK method. The FSK method allows transmission of character data as well as the number and a data transmission in an ON-hook state and an OFF-hook state, so that it is suitable to provide the CID service.
If a new call set-up is requested when the destination phone set is in the OFF-hook state, the CID data processing unit 210 of the destination exchange 200 transmits a specific tone signal to the destination phone set through a speech path of the previously established call. Then, the CID modem 130 recognizes the specific tone signal, according to a control signal of the controller 140, and transmits a response signal to the CID data processing unit 210. The CID data processing unit 210 transmits CID data of the call, which has requested a set-up, to the CID modem 130. Then, the destination phone set performs an FSK demodulation and a signal conversion for the CID data and displays it on the LCD panel 110. In this manner, the subscriber can identify the caller through the LCD panel 110, even for a subsequently received phone call which is made while the subscriber is on a prior call communication, so that the subscriber can take a proper step for the other call.
As stated above, the transmission form of the background CID service system is a unidirectional transmission from the CID data processing unit 210 to the CID modem 130 of the subscriber. Thus, it is limited in utilizing the CID more positively.
In addition, since the CID data is stored in the memory of the destination phone set, there is no way for the subscriber to check the CID data without the destination phone set.
This kind of spatial restriction for information and the low equipment use efficiency of the uni-directional transmission have been noticed as the major shortcomings of the CID service system.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
Another object of the present invention is to provide a bi-directional CID service apparatus and method that enable an external communication unit to read CID data stored in a destination phone set.
To achieve at least the above objects in whole or in part, there is provided a bi-directional CID service providing apparatus including: a CID unit of a destination phone set having functions of displaying, storing, transmitting, and receiving CID data of a destined call; a call-originating terminal unit that transmits a CID data request signal to the CID unit of the destination phone set and receives corresponding CID data; and a CID unit of a destination exchange that transmits a xe2x80x98CID data transmission control signalxe2x80x99 to the destination phone set, receives the corresponding CID data, and transmits the CID data to the call-originating terminal unit.
To achieve at least these advantages in whole or in part, there is further provided a bi-directional CID service providing method including checking whether a xe2x80x98CID data request signalxe2x80x99 has been received, while receiving a call set-up request signal from a call-originating terminal unit; searching a CID service DB to check whether a destination phone number is a registered one, if the xe2x80x98CID data request signalxe2x80x99 has been received upon checking; transmitting a xe2x80x98CID data transmission control signalxe2x80x99 requesting transmission of CID data from the destination phone set, if the destination phone number has been registered in the DB according to the DB searching result; and transmitting the CID data to the call-originating terminal unit, when the CID data is transmitted from the destination phone set.
The objects of the invention may be achieved in whole or in part by a bi-directional Calling Identity Delivery (CID) device, including a CID communication unit that converts received modulated signals to received baseband signals and converts transmit baseband signals to transmit modulated signals; a CID controller that determines whether a call is a general call or a bi-directional CID service call, based on the received baseband signals; a memory that stores a CID database; and a CID service manager that generates CID information, if a destination terminal identified in the received baseband signals is registered in the CID database, under the control of the CID controller. The CID communication unit converts the CID information to the transmit modulated signals for external transmission.
The objects of the invention may be further achieved in whole or in part by a bi-directional Calling Identity Delivery (CID) method, including determining whether a call is a general call or a bi-directional CID call, based on a received call setup signal; transmitting originating party CID information to a destination terminal if the destination terminal identified in the call set-up signal is registered in a CID database; and transmitting answering party CID information received from the destination terminal to an originating terminal of the bi-directional CID call.
The objects of the invention may be further achieved in whole or in part by a method of retrieving call information, including storing telephone call connection information at a first subscriber unit and retrieving the call connection information from the first subscriber unit through a telephone call using a second subscriber unit.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.